The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
The inventor(s) has noted that since moving image data is large in size, a compression process is required so as to store or transmit the moving image data. Typically, moving image data is encoded by performing intra prediction or inter prediction, transform, quantization, and entropy coding on each picture of the moving image data in units of blocks. Prediction is performed so as to reduce data redundancy in moving images. Data redundancy can be reduced by utilizing intra prediction in which prediction is performed based on neighboring blocks by using spatial redundancy, or by utilizing inter prediction in which motion estimation and motion compensation are performed by using temporal redundancy. The inventor(s), however, has experienced that in the bad case of prediction, some components having large values may be included in a residual signal generated by the prediction. Further, the inventor(s) has experienced that the presence of badly predicted components may degrade compression performance.